Pressing device for producing compressed bales of straw

Abstract

A pressing device for producing compressed bales of straw comprises two press chambers disposed at opposite ends and two press slides, one for each press chamber, wherein the two press slides are driven by means of a common drive unit located between the two press chambers disposed at opposite ends.

Description

[0001] Jürgen Holz, February 4, 2026, Backnang

[0002] Pressing device for the production of pressed bales from straw

[0003] The invention relates to a pressing device for the production of pressed bales from straw.

[0004] It is known to construct modular building elements in the form of rectangular wooden frames with multiple compartments, into which compressed straw bales are inserted for thermal and acoustic insulation. Such a building element in timber frame construction is described, for example, in AT 510 797 Al. This building element can be used, for instance, as an exterior or interior wall for residential buildings or other structures.

[0005] To comply with legal regulations, especially with regard to strength, insulation properties, but also fire and insect protection, it is necessary to manufacture the straw bales with a high material density and high dimensional accuracy.

[0006] Publication US 956 111 A shows a hay baler with two opposing receiving chambers and a pressing device which has a pressing bar which is driven by an eccentric lever 6 and performs a forward and reverse movement, wherein the eccentric lever is rotatably mounted on a frame and is manually adjustable by means of a hand lever.

[0007] The invention is based on the objective of creating a pressing device with simple design measures which is suitable for efficiently producing pressed straw bales suitable for use in building walls.

[0008] This problem is solved according to the invention by the features of claim 1. The dependent claims specify advantageous further developments.

[0009] The press device according to the invention for producing straw bales that can be used in building walls has at least a first and a second press chamber for receiving straw, each press chamber being assigned a press slide for compressing the straw in the press chamber. Each press slide is adjustable between a retracted starting position and a forward press position in which the straw in the press chamber is subjected to a pressing force. The two press slides are driven by means of a common drive unit located between the two opposing press chambers. The drive unit is configured such that the two press slides perform opposite movements, in particular translational movements, when moving between the starting position and the press position. This press device has several advantages.Firstly, despite the increased output of bales, the press according to the invention is subjected to only relatively low forces, even though a significant pressing force is required to produce the bales, with which each press carriage applies pressure to the straw in the press chamber. This reduction in force is achieved by the inventive design of the drive unit in the press, which is arranged, in particular, centrally between the two opposing press chambers and sets the two press carriages in opposite directions. Accordingly, the pressing forces acting on the straw in each press chamber are also directed in opposite directions. Due to the opposing movement of the press carriages, the dynamic forces in the drive unit cancel each other out or are at least significantly reduced.The same applies to the reverse movement when transferring from the pressing position to the starting position, since in this case, too, the respective return movements of the two press slides are directed in opposite directions, and the forces therefore cancel each other out. Particularly at the reversal points of the movement during the transition from the pressing direction to the return direction and vice versa, which are each associated with high forces, the forces in the drive mechanism cancel each other out or largely cancel each other out.

[0010] In this way, the components of the drive unit are at least largely relieved of the dynamic forces that occur at the reversal points of the press slides. Furthermore, the other components of the press, particularly those firmly fixed to the ground, such as a support frame, are also relieved of the high forces that occur during the movement of the press slides. This also ensures that the entire press is not subjected to increased shocks, vibrations, or oscillations during operation, which could disrupt the pressing process and potentially damage components of the press.

[0011] Secondly, the baling machine can be operated more efficiently by simultaneously filling both baling chambers with straw and compressing the straw into a bale. In this mode, the baling machine achieves a higher production rate of bales per unit of time than a baling machine with only one chamber.

[0012] Alternatively, it is also possible to fill only one of the press chambers with straw and compress it by the associated press carriage. In this configuration as well, the two press carriages perform opposing movements, thereby significantly reducing the dynamic forces in the drive mechanism.

[0013] The drive unit comprises an eccentric device for adjusting the two press slides in opposite directions. The drive unit includes a motor-driven drive pulley that drives the two opposing press slides, with the connection between the drive pulley and the two press slides being made via the eccentric device. This device comprises two connecting rods, one of which is assigned to each press slide. One end of each connecting rod is directly or indirectly, in particular by pivot, connected to the drive pulley, and the other end is pivotally connected to the press slide at a distance from the axis of rotation of the drive pulley. Advantageously, at least one drive shaft of the drive pulley is rotatably mounted in the press, with the two connecting rods arranged axially offset from each other with respect to the axis of rotation of the drive shaft or drive pulley.This ensures that both press slides can be driven via the axially offset connecting rods and that the drive disc can perform a continuous rotational movement without reversing the rotation for the pressing process and the return process of the press slides.

[0014] The eccentric device converts the rotary drive movement of the drive disc into a preferably translational sliding movement of the press slides. The press slides can optionally be mounted in guide rails or similar devices within the press fixture, either rolling or sliding, to achieve a defined movement pattern.

[0015] The drive shaft of the drive disc is rotatably mounted in a support frame of the press, which accommodates both the press chambers and the drive unit. The drive unit shaft, extending orthogonally to the adjustment direction of the press slides, advantageously has three bearing points along its axial length, located at the ends and in the middle of the shaft. The connecting rods are pivotally coupled to each drive arm, with the two drive arms being rotatably connected to the drive shaft and advantageously located on opposite axial sides of the central bearing point of the drive shaft. This ensures that dynamic forces acting on the shaft due to the axial offset of the two connecting rods and the press slides are distributed evenly across the support frame of the press. At least one bearing is provided for each bearing point.

[0016] According to yet another advantageous embodiment, the press has two further press chambers, also arranged opposite each other, parallel to the first two opposing press chambers. Each of these additional press chambers is also assigned a press slide and a common, additional drive unit. The design of the additional drive unit is identical to that of the first drive unit, which drives the first two press slides. This embodiment doubles the capacity. Advantageously, the production of straw bales in the additional press chambers can be carried out independently of the straw bale production in the first two press chambers. For this purpose, the two drive units can be operated independently of each other. The design is particularly symmetrical with respect to a central longitudinal axis of the press.The drive units can be arranged symmetrically to each other and be of identical construction. The drive shafts of the drive units, to which the connecting rods are fixedly mounted and which serve to drive the press slides, are coaxial to each other, but they are independently mounted and designed separately. Each drive unit also has its own drive motor, in particular an electric motor, which, for example, drives the respective drive pulley via a belt.

[0017] Alternatively, a single drive unit can be used for both drive systems.

[0018] According to a further advantageous embodiment, each press chamber is assigned at least one additional pressing device in addition to the press carriages. This device allows for the adjustment of a movable wall of the press chamber or an adjustment plate on the inner wall. In a preferred embodiment, the press chamber has an open side on the side of the assigned press carriage to allow the straw to be fed into the press chamber via the press carriage. The additional pressing device, on the other hand, is able to adjust a movable wall of the press chamber, which advantageously adjoins the open side of the press chamber, and also apply a pressing force to this wall. This makes it possible to compress the bale from two different sides, resulting in improved dimensional accuracy of the straw bale and a more uniform density.

[0019] It may be advantageous to additionally arrange pressing devices on two different movable walls of the press chamber that adjoin each other, so that it is possible to apply a pressing force to the press bale in all three spatial directions. At least, however, in a preferred embodiment, the upper wall of the press chamber is movable and the additional pressing device is located above the press chamber.

[0020] As an alternative to the top wall, a side wall of the press chamber can also be designed to be movable.

[0021] The additional pressing device can move a wall of the pressing chamber or a positioning plate that is part of the wall or is designed independently of the wall and is located on the inside of the wall.

[0022] The additional pressing device is preferably hydraulically or pneumatically designed and accordingly includes a hydraulic or pneumatic actuating cylinder.

[0023] The additional pressing device can also be designed in such a way that the press bale is pushed out of the press chamber by the pressing device and pushed under a wedge device, whereby the press bale also experiences a compressing force.

[0024] According to yet another advantageous embodiment, the baling device has a straw feed unit for conveying straw to a storage point located in front of the baling chamber. The storage point is situated in front of the open side of the baling chamber, so that the straw conveyed to the storage point is caught by the baling carriage and pressed into the baling chamber. It is particularly advantageous for the baling carriage to continuously perform a forward pressing movement and a reverse retraction movement, with the storage point for the straw being exposed in the retracted starting position, so that straw can be conveyed to the storage point by actuating the straw feed unit. In the next cycle, this straw can again be pressed into the baling chamber by the advancing baling carriage.

[0025] Possible configurations include systems where, at each retracted starting position of the press carriage, straw is conveyed to the storage point in front of the press chamber via the straw feed device. Alternatively, it is also possible to activate the straw feed device and convey straw to the storage point in front of the press chamber not at every retracted starting position, but only at some of the retracted positions of the press carriage.

[0026] According to another advantageous embodiment, the straw feed device is located below the press chamber and the straw is gathered from a delivery point below the press chamber by means of the straw feed device and conveyed upwards to the depositing point immediately in front of the press chamber.

[0027] In an alternative design, straw is fed into the press chamber not from below, but from above or from the side.

[0028] The straw feeding device advantageously comprises a conveying arm and a conveying channel, the operation of which conveys straw from a delivery position via the conveying channel to the depositing point in front of the opening of the baling chamber. The conveying arm is, in particular, articulated and performs a pivoting movement during the conveying motion. The conveying motion includes gathering or grasping the straw deposited in front of the conveying channel and conveying the straw via the conveying channel to the depositing point. It may be advantageous for the conveying arm to perform two different movements during the conveying motion. These are, in particular, superimposed or sequential movements involving two rotary pivoting motions. Each movement can be assigned its own drive unit, in particular an electric drive motor.

[0029] According to yet another advantageous embodiment, the pressing device has an ejection mechanism for pushing the press bales out of the pressing chamber. After the press bales are completed, they are initially still in the pressing chamber and are pushed out of the pressing chamber by means of the ejection mechanism, which in particular comprises an ejection cylinder. The ejection cylinder acts on a sliding plate located on the inside of a wall of the pressing chamber, the ejection cylinder projecting through a recess in the wall and adjusting the sliding plate to eject the press bale. Advantageously, the ejection direction is orthogonal to the adjustment direction of the press carriage and also orthogonal to the adjustment direction of the additional pressing device, via which a wall of the pressing chamber is adjustable.To carry out the ejection, it is advantageous to open the wall of the press chamber opposite the ejection device to allow for the desired ejection path. The pressed bale is preferably ejected to a collection platform on the press, where it can be deposited. Alternatively, instead of a collection platform, the pressed bale can be ejected towards a robot gripper or inserted into a receptacle of a robot gripper. The robot gripper then picks up the pressed bale and transports it to its next use.

[0030] Instead of an extension cylinder, an electrically adjustable spindle can also be used.

[0031] The invention also relates to a method for actuating the aforementioned press device. The drive unit is configured such that the press carriage is continuously moved back and forth in only one direction of rotation during a continuous rotation of the drive disc. This occurs, for example, at a frequency of preferably one to three, for example two, adjustment movements per second, in which the press carriage is moved between the retracted starting position and the advanced pressing position. Advantageously, the movement of the straw feed device is synchronized with the movement of the press carriage, so that, for example, straw is conveyed to the storage point between the press chamber and the retracted press carriage in every retracted position.If necessary, it may also be expedient to convey straw to the storage point not at every withdrawn starting position, but only at every second, every third, etc. withdrawn starting position.

[0032] During operation of the baling machine, it may be advisable to fill only one of the two opposing baling chambers with straw. However, it is also possible to fill both baling chambers with straw simultaneously. The drive unit encompassing the baling carriages allows the straw in the baling chamber to be subjected to a high pressing force. This force is typically between 1 ton and 10 tons, for example, 6.5 tons. A sensor, such as a load cell mounted in or on a wall of the baling chamber, can be used to evaluate the pressing force.

[0033] The additional pressing device, which allows for the adjustment of a movable wall within the press chamber, can also be adjusted with a high pressing force in a range between 200 kg and 5 t, for example, 2 t. In this case, it may be advantageous to install sensors in or on the press chamber to determine and monitor the pressing force.

[0034] Advantageously, the drive mechanism for adjusting the two press slides is electrically operated, comprising an electric drive motor. The additional press mechanism for adjusting a chamber wall is expediently hydraulically operated and includes a hydraulic actuator. The ejection mechanism for pushing out finished bales is expediently hydraulically operated. The straw feed mechanism for conveying straw to the storage area in front of the press chamber is advantageously electrically operated and includes at least one electric drive motor, optionally two electric drive motors.

[0035] The drives for the straw feeding device, the drive device, the pressing device and the ejection device can be either electric, electromechanical, hydraulic or pneumatic.

[0036] The geometry of the press chamber can be variable. In particular, it is possible to adjust the length, width, and / or height of the press chamber depending on the type of bale being produced. Furthermore, it can also be advantageous to design the geometry of the press carriage to be variable.

[0037] Further advantages and practical designs can be found in the additional requirements, the figure description, and the drawings. These show:

[0038] Fig. 1 shows a side view, partly in section, of a press device for producing pressed bales from straw, with two opposing press chambers with a drive device for driving two press slides, each assigned to a press chamber, and with two straw feed devices arranged below the press chambers.

[0039] Fig. 2 shows the pressing device in side view without section,

[0040] Fig. 3 shows the press without depicting the straw feed device, with the drive device in an 0° position (retracted basic or...

[0041] Starting position), Fig. 4 shows the press device with the drive unit in a 90° position, in which the press slides are moved towards the press chambers,

[0042] Fig. 5 shows the press device with the drive unit in a 180° position (advanced press position), in which the press slides are adjusted maximally in the direction of the press chambers,

[0043] Fig. 6 shows a top view of the press device with two drive units, each having two press slides for two opposing press chambers.

[0044] Fig. 7 shows a top view of the press device corresponding to Fig. 6, with identification of the press slides and press chambers belonging to a drive unit.

[0045] Fig. 8 shows a front view of the pressing device with an additional upper pressing device for adjusting the upper wall of the pressing chambers and with an ejection device for ejecting finished pressed bales.

[0046] Fig. 9 shows a representation corresponding to Fig. 8, but with the upper wall of the press chambers in a lowered position.

[0047] In the figures, identical components are labeled with the same reference numerals. The depicted press 1 is used to produce pressed straw bales, which can be used in wall elements of buildings, particularly for insulation. The pressed straw bales produced by the press 1 can be manufactured from delivered straw material with predetermined dimensions, a desired density, and a specific orientation of the straw stalks.

[0048] The press 1 comprises a support frame 2, which stands on a frame or supports 3 and accommodates a total of four press chambers 4, which are labeled A, B, C, and D in Fig. 6, with two press chambers 4 arranged opposite each other. Each press chamber 4 has one open side. The open sides of opposite press chambers 4 face each other. Press slides 6 are actuated by a drive unit 5 to push straw, which is located at a storage point directly in front of the press chambers 4, into the press chambers 4 and compress it with pressing force in each press chamber 4. One press slide 6 is assigned to each press chamber 4.

[0049] Each press chamber 4 is also assigned a straw feed device 7, which is located on the floor below the support frame 2. The straw feed device 7 gathers straw from a delivery position at floor level and conveys it upwards to the depositing point 8, which is located directly in front of an opening of the press chamber 4. The straw feed device comprises a motor-driven upfeeder 9 and a curved conveying channel 10, which extends from the delivery position at floor level to the depositing point 8 in front of the press chamber 4. The upfeeder 9 is motor-driven and connected to the drive via a kinematic mechanism, enabling the upfeeder 9 to move along the curve of the conveying channel 10.

[0050] The drive unit 5 simultaneously drives two opposing press slides 6, as shown in Fig. 7 with the two double arrows.

[0051] A total of two drive units 5 are provided for the four press chambers 4, each drive unit 5 comprising two press slides for two opposing press chambers 4. The two drive units 5 can be operated independently of each other. The drive units 5 are located on opposite sides of a central longitudinal axis of the press device 1 and are of identical construction. Each drive unit 5 comprises a rotatably mounted drive pulley 11, which is driven by an electric drive motor 13 via a belt or chain 12.An eccentric device converts the rotary motion of the drive disc 11 into a translational back-and-forth motion of the two press slides 6, which are adjustable along the central longitudinal axis of the press device 1 between a retracted starting position and a forward pressing position in which the straw in the press chamber 4 is subjected to a pressing force. The retracted starting position is shown in Fig. 3, the forward pressing position in Fig. 5, with Fig. 4 representing an intermediate position between the starting and pressing positions.

[0052] The eccentric device comprises a connecting rod 14 for each press slide 6, wherein the two connecting rods 14 are pivotally coupled at one end to a drive arm 15 rotating with the drive disc 11 and pivotally coupled at the other end to the press slide 6. Each connecting rod 14 is associated with a drive arm 15, which is non-rotatably connected to a drive shaft 16. The drive shaft 16 is in turn non-rotatably connected to the drive disc 11 and has the same axis of rotation as the drive disc 11. The drive shaft 16 extends transversely to the press 1, i.e., transversely to the longitudinal center axis of the press 1. The pivot points of the two connecting rods 14 on their respective associated drive arms 15 are offset from each other by 180°, as can be seen, for example, in Fig. 4. The offset in the transverse direction – or the axial offset with respect to the axis of rotation of the drive disc and the drive shaft – can be seen in particular in Figs. 6 and 7, where in Fig.Figure 7 shows the offset with the angled double arrow. Accordingly, the two opposing press chambers 4 are also positioned with a corresponding offset from each other.

[0053] With the help of the drive unit 5, it is possible, on the one hand, to ensure a significantly reduced force design due to the simultaneous adjustment of the two press slides 6 into the advanced press position or during the return process into the withdrawn starting position.

[0054] Both connecting rods 14 and the press slides 6 attached to them are simultaneously at the reversal point between pressing and retraction, and at the reversal point between retraction and pressing. Accordingly, forces do act on the drive shaft 16, but the other components of the press device 1, in particular the support frame 2 with the bearings for the drive shaft 16, are largely relieved of dynamic pressing forces or retraction forces.

[0055] It is also advantageous that the drive disc 11, as shown in Fig. 4 with the curved arrow, only needs to be driven continuously in one direction of rotation to perform the desired continuous translational pressing movement – ​​as indicated by the straight arrows in Fig. 4 – as well as the return movement. It is not necessary, however, to reverse the direction of rotation of the drive disc 11.

[0056] The drive shaft 16 for each drive unit 5 has three bearing points 17, 18, 19 along its axial length, as can be seen in Fig. 6. The two bearing points 17 and 19 are located at the two end faces of the drive shafts 16, whereas the middle bearing point 18 is located in the center. The two connecting rods 14, each driving a press slide 6, are located on either side of the middle bearing point 18. The bearing point 19 in the center of the press has two bearings, each assigned to a drive shaft 16 for each drive unit.

[0057] In Fig. 7, which also shows a top view of the press 1, a dividing line 20 is shown between the two double arrows. This line runs along the longitudinal center axis of the press 1 and symbolically separates the two drive units 5. The dividing line 20 passes through the bearing 19, which serves as a bearing for both drive shafts 16. The two drive units 5 can be actuated independently of each other. Each drive unit 5 is assigned an electric drive motor 13. Due to the independent control, it is possible to actuate either only one of the two drive units 5 or both drive units 5 simultaneously.

[0058] During the pressing movement of the press carriages 6 across the open side of the press chambers 4, the walls of the press chambers 4 remain stable and immobile. After completion of the pressing process, the press carriages 6 initially remain in their furthest advanced pressing position, whereupon an upper, movable wall or cover 21 of the press chambers 4 is lowered by means of a hydraulically actuated pressing device 22 (Figs. 8, 9) to apply an additional pressing force to the straw bale in the press chamber 4 from another side. A pressing force in a range between 1 t and 10 t, for example a pressing force of 6.5 t, can be generated by the press carriages 6 and applied to the bale. The upper pressing device 22 allows for further pressing from another side by lowering the wall or cover 21.A pressing force of between 200 kg and 5 t, for example 2 t, is exerted on the press bale by the lid 21. The lowering of the wall or the lid 21 can be seen in the comparison of the two figures 8 and 9.

[0059] After the straw bales have finished pressing, they can be pushed laterally out of the pressing chambers 4 using a hydraulic ejection device 23. The press carriages 6 remain in the extended pressing position, and the wall or lid 21 remains in the lowered position during the ejection movement. As can be seen particularly in Figures 6 to 9, the ejection device 23 is located in the side area, with a total of two such ejection devices 23 being provided, each of which removes bales from two pressing chambers 4 located on the same side of the pressing device, which belong to different drive units 5. According to Figure 6, an ejection device 23 arranged on the left can remove bales from the two pressing chambers 4 labeled A and C, whereas the ejection device 23 arranged on the right can push bales out of the two pressing chambers 4 labeled B and D.To carry out the ejection process, the side walls 24 of the press chambers 4 (Fig. 8) are pulled out or, if necessary, lowered, so that an ejection path is cleared up to a collection platform f 25 (Figs. 6, 7), on which the ejected press bale can be collected for further processing. When the ejection device 23 is actuated, a sliding plate 26 (Figs. 8, 9), which is located on the inner wall of the press chamber wall nearest to the ejection device 23, is moved to eject the press bale.

[0060] Instead of a collection platform, the press bale can be pushed out towards a robot gripper or inserted into a receptacle of a robot gripper.

[0061] The movements of the straw conveying device 7 and the drive devices 5 are coordinated so that, in the retracted position of the press carriages 6, straw is conveyed upwards to the depositing point 8, which, during the subsequent pressing movement of the press carriages 6, is conveyed into the chambers 4 and compressed there. The frequency of the press carriages 6 is preferably between one and three movements per second, and, for example, at least two movements per second between the retracted starting position and the advanced pressing position.

[0062] Advantageously, the pressing force is monitored. Suitable sensors are provided for this purpose, which can measure and monitor both the pressing force of the press slides 6 and the pressing force of the upper pressing device 22.

Claims

Jürgen Holz, February 4, 2026, Backnang Patent claims 1. Pressing device for producing pressed bales from straw, comprising a first and a second pressing chamber (4) for receiving straw, wherein each pressing chamber (4) is assigned a pressing slide (6) for compressing the straw in the pressing chamber (4), and the pressing slide (6) is adjustable between a retracted starting position and a forward pressing position in which the straw in the pressing chamber (4) is subjected to a pressing force, wherein the two pressing slides (6) are driven by means of a common drive device (5) located between the two opposing pressing chambers (4), wherein the two pressing slides (6) perform opposite movements when moving between the starting position and the pressing position, characterized in that the drive device (5) comprises an eccentric device for adjusting the two pressing slides (6) in opposite directions.that the eccentric device for each press slide (6) comprises a rotatingly driven connecting rod (14) to which the press slide (6) is pivotally connected at a distance from an axis of rotation, that the two connecting rods (14) are arranged axially offset from each other with respect to the axis of rotation of the drive unit (5), that the drive unit (5) comprises a motor-driven drive disc (11) via which the two opposing press slides (6) are driven, that the drive disc (11) is connected to a drive shaft (16) which is rotatably mounted in a support frame (2) of the press device (1), and that the connecting rods (14) are arranged on axially opposite sides of a central bearing point (18).

2. Pressing device according to claim 1, characterized by that parallel to the first two opposing press chambers (4) there are two further press chambers (4) also arranged opposite each other, to which each is assigned a press slide (6) and a common drive unit (5) which is constructed in the same way as the drive unit (5) of the first two press slides (6) .

3. Pressing device according to claim 2, characterized by that the two drive devices (5) can be operated independently of each other.

4. Pressing device according to one of claims 1 to 3, characterized in that, that each press chamber (4) is assigned at least one further press device (22) in addition to the press slides (6), via which a movable wall (21) of the press chamber (4) is adjustable.

5. Press device according to claim 4, characterized by that an upper wall (21) of the press chamber (4) is movable and the press device (22) is located above the press chamber (4).

6. Pressing device according to one of claims 1 to 5, characterized in that, that the press device ( 1 ) has a straw feed device (7 ) for conveying straw to a storage point ( 8 ) in front of the press chamber (4 ).

7. Pressing device according to claim 6, characterized by that the straw feed device (7 ) is arranged below the press chamber (4 ) and the straw can be conveyed from a lower delivery position to the depositing point ( 8 ) using the straw feed device (7 ).

8. Pressing device according to one of claims 1 to 7, characterized in that, that the pressing device ( 1 ) has an ejection device (23) for ejecting press balls from the pressing chamber (4 ).

9. Pressing device according to claim 8, characterized by that the ejection device (23) acts upon a sliding plate (26) which is located on the inside of a wall of the press chamber (4).

10. Pressing device according to claim 8 or 9, characterized by that a collection plate form (25) is arranged laterally on the press device ( 1 ) onto which an ejected press bale can be deposited .

11. Method for actuating the press device according to one of claims 1 to 10, wherein the drive device (5) is actuated in such a way that, to produce a press ball, a press slide (6) is moved between the retracted starting position and the advanced press position at a frequency of one to three times per second.

Images